You missed my vote, so that makes 4 ;o) No caliber has impressed me more in the game fields than the 7mm Remington mag. I shoot a lot of stuff and a lot of calibers, but the 7mm just crunches stuff. I sure do have a soft spot for the 7mm-08 though. Very impressive round.
Get both rifles, take the scope off the one and put it on the .280 with good DUAL DOVE TAIL mounts, then sell the heavier 7mm. Flinch.